Data available through: 2020-05-25
I am restricted the charts to show values on March 15, 2020 and after. This is when preventative measures started to increase dramatically. In addition, given the small number of cases prior to this date caused great variability in the growth rate and has multiple instances where it’s NA or equal to infinity.
These show the cumulative total of cases and deaths. These total values are important; however they are not helpful for figuring out whether the pandemic is slowing down or growing.
Looking at new cases each day can help us see if the pandemic is slowing (new cases per day is decreasing).
There can be a lot of variability in the daily points - this is due to many different variables. On variable is the availability of tests, cases will go down if there is scarcity of tests and rise dramatically when more tests become available. One way to help get a better sense over the overall trend is by smoothing the data.
I also wanted to look at the dealth percentage which I calculated as the total number of deaths divided by the total number of cases for a given day.
| Date | Total Cases | New Cases | Total Deaths | New Deaths | Death Percentage |
|---|---|---|---|---|---|
| Mon, May 25, 2020 | 1,654,081 | 19,542 | 97,285 | 699 | 5.882% |
| Sun, May 24, 2020 | 1,634,539 | 21,726 | 96,586 | 665 | 5.909% |
| Sat, May 23, 2020 | 1,612,813 | 22,842 | 95,921 | 1,115 | 5.947% |
| Fri, May 22, 2020 | 1,589,971 | 23,378 | 94,806 | 1,200 | 5.963% |
| Thu, May 21, 2020 | 1,566,593 | 26,007 | 93,606 | 1,332 | 5.975% |
| Wed, May 20, 2020 | 1,540,586 | 22,093 | 92,274 | 1,496 | 5.990% |
| Tue, May 19, 2020 | 1,518,493 | 20,611 | 90,778 | 1,537 | 5.978% |
| Mon, May 18, 2020 | 1,497,882 | 21,622 | 89,241 | 1,018 | 5.958% |
| Sun, May 17, 2020 | 1,476,260 | 18,518 | 88,223 | 762 | 5.976% |
| Sat, May 16, 2020 | 1,457,742 | 24,514 | 87,461 | 1,081 | 6.000% |
| Fri, May 15, 2020 | 1,433,228 | 24,906 | 86,380 | 1,458 | 6.027% |
| Thu, May 14, 2020 | 1,408,322 | 26,810 | 84,922 | 1,772 | 6.030% |
| Wed, May 13, 2020 | 1,381,512 | 20,616 | 83,150 | 1,680 | 6.019% |
| Tue, May 12, 2020 | 1,360,896 | 21,506 | 81,470 | 1,640 | 5.986% |
Data available through: 2020-05-25
One important calculation is the growth factor, as outline in 3Blue1Brown’s youtube video on exponential growth . The growth rate is calculated as follows:
\[ \text{Growth Factor} = \frac{ \text{New-Cases}_N}{\text{New-Cases}_{N-1}} \] where \(N\) is a given day.
In order to see if the pandemic is slowing down, it is helpful to look at the growth factor and the daily new cases. For both these values; we want to see a decrease in values from day to day - which indicates that less people are getting sick. Recall that a growth factor less than 1 is a positive sign that the growth of cases is slowing down. Growth factor is directly related to new cases - if daily new cases goes now the growth factor is less than 1; if daily cases goes up the growth factor is greater than one. These two charts represent the same information in two differnt ways.
There can be a lot of variability in the daily points - this is due to many different variables. On variable is the availability of tests, cases will go down if there is scarcity of tests and rise dramatically when more tests become available. One way to help get a better sense over the overall trend is by smoothing the data.
| Date | Total Cases | New Cases | Growth Factor |
|---|---|---|---|
| Mon, May 25, 2020 | 1,654,081 | 19,542 | 0.9 |
| Sun, May 24, 2020 | 1,634,539 | 21,726 | 0.95 |
| Sat, May 23, 2020 | 1,612,813 | 22,842 | 0.98 |
| Fri, May 22, 2020 | 1,589,971 | 23,378 | 0.9 |
| Thu, May 21, 2020 | 1,566,593 | 26,007 | 1.18 |
| Wed, May 20, 2020 | 1,540,586 | 22,093 | 1.07 |
| Tue, May 19, 2020 | 1,518,493 | 20,611 | 0.95 |
| Mon, May 18, 2020 | 1,497,882 | 21,622 | 1.17 |
| Sun, May 17, 2020 | 1,476,260 | 18,518 | 0.76 |
| Sat, May 16, 2020 | 1,457,742 | 24,514 | 0.98 |
| Fri, May 15, 2020 | 1,433,228 | 24,906 | 0.93 |
| Thu, May 14, 2020 | 1,408,322 | 26,810 | 1.3 |
| Wed, May 13, 2020 | 1,381,512 | 20,616 | 0.96 |
| Tue, May 12, 2020 | 1,360,896 | 21,506 | 1.21 |
Data available through: 2020-05-25
Data available through: 2020-05-25
Data available through: 2020-05-25
This data is downloaded from USA Facts CDC. I use two of the three spreadsheets, one with total cases and one with total deaths - both broken down by state and county. This data requires additional formating, calculation, and aggregation. USA Facts gets data by county on a daily basis, this is totaled to get values for each day for the entire US.
The American CDC links to USA Facts under Cases & Death by County, which is how I found the data source.